1. Field of the Invention
The present invention relates to a method of assay. More particularly, the present invention relates to a method of assay for prostaglandins of the E and F series.
2. Background of the Prior Art
Prostaglandins are a group of unsaturated hydroxy and hydroxy-keto long-chain carboxylic acids. These are widely distributed in human and animal tissues and possess a wide variety of pharmacological actions. It seems probable that prostaglandins have a biochemical role fundamental to many, perhaps all, animal cells. Many articles have been devoted to the prostaglandins especially the biochemical/pharmacological aspects. A recent review entitled, "Hypothesis on Physiological Roles of Prostaglandins" by E. W. Horton, Physiological Review, Volume 49, No. 1, January, 1969, reviews the present status of the knowledge on the functional significance of the prostaglandins.
Naturally occurring prostaglandins are 20-carbon fatty acids containing a cyclopentane ring. The parent saturated acid has been named prostanoic acid as drawn below: ##SPC1##
Two important series of natural prostaglandins are designated by the letters E and F corresponding to differences in the ring, as shown below: ##SPC2##
All of the prostaglandins have a 15-hydroxyl substituent. The degree of unsaturation of the side chains is indicated by the subscript numeral after the letter: thus prostaglandin E.sub.1 has a trans double bond in the 13 position, E.sub.2 has, in addition, a cis double bond in the 5 position, E.sub.3 has a third double bond in the 17 position, etc. The structural formulas of 14 naturally occurring prostaglandins are shown in FIG. 3 of the Horton reference, supra.
Prostaglandins have a wide variety of pharmacological actions, being active in such diverse areas as fertility, transport of sperm, menstruation, parturation, placental blood flow, gastric secretion, muscle contractility (including vascular smooth muscle, respiratory smooth muscle, gastrointestinal smooth muscle, uteral smooth muscle, and spleenic capsular smooth muscle), development of epidermal tissues and central nervous transmitters. Prostaglandins are also thought to affect permeability, e.g., the skin and the eye. Thus, it has been suggested that prostaglandins may act as mediators of various forms of inflammation. This role in inflammation is strongly supported by the involvement of prostaglandins in the inflammatory process in joints, skin, and eyes.
While assay methods are known for prostaglandins, they are generally difficult and/or inaccurate and/or inconvenient and time consuming. Furthermore, unknown compounds in variable biological samples, e.g. blood, urine, tissue, can make it difficult or impossible to obtain an accurate assay with methods known heretofore.